This invention relates to a portable device of the kind including a mechanism comprising a source of energy, a rotary drive member supplied by the source and a gear-train driven by the rotary drive member.
Portable devices of this kind include, for instance, wrist watches and pocket watches. The aesthetics appearance of such watches is generally determined by the case, the dial and the hands. In some watches of more original design, known as skeleton watches, the movable parts are visible at least to some extent.